The present invention is directed to article handling apparatus operable in a production line environment to turn articles, such as a vehicle wheel, from a horizontal position in which a first side of the article faces upwardly to an inverted position in which the article is again positioned horizontally, but with its opposite side facing upwardly.
The invention is disclosed as applied to the turning of a vehicle wheel assembly consisting of a wheel carrying a mounted and inflated tire in conjunction with the mounting of weights upon the wheel rim to rotatively balance the assembly.
In present-day tire-wheel assembly lines the wheel and tire units pass successively through a mounter where an uninflated tire is mounted upon its wheel, as inflation station at which the mounted tire is inflated, and a balancing station at which rotative imbalance of the assembled wheel and tire is determined and then to a work station where a worker applies lead weights to the wheel rim to correct the rotative imbalance determined by the balancer. The tire-wheel unit is conveyed through the mounter, inflator and balancing stations with the unit disposed in a horizontal position (wheel axis vertical) with what will be the outer side of the unit when assembled on a vehicle facing upwardly. Particularly for passenger vehicle wheels, for cosmetic reasons it is desired to mount the balancing weights, where possible, on the inner side of the wheel; and it is thus necessary to invert the wheel unit so that the worker applying the weights has access to the inner side of the wheel. After the balancing weights have been applied to the inner side of the wheel rim, it is then necessary to reinvert the wheel unit to its original outside-up position so that all wheels come off the end of the line in the same orientation.
The present invention is especially directed to a turnover device which will handle tire-wheel units of varying dimensions (as is requrid in nearly all present-day tire-wheel assembly production lines) while accommodating straight-through conveyance of the units through the turnover device.
Turnover devices in general are used in many industrial applications, typically to turn relatively large or bulky articles, such as steel plate or sheet metal parts. The present invention employs two pair of arms respectively mounted for pivotal movement about spaced, parallel, horizontal axes normal to the path of conveyance. Examples of prior art devices employing two sets of pivoted arms for turning over steel plate or sheet metal parts are found in U.S. Pat. No. 3,780,882; to Wagner U.S. Pat. No. 3,581,910; and U.S. Pat. No. 4,533,291. to Nishida. All three of these patents disclose turnover devices in which a flat article to be turned over is loaded upon a first pivoted arm assembly which provides the entire support for the article with the article in a horizontal position and then pivots about a horizontal axis to pivot the article upwardly to a generally vertical position. With the article in or close to a vertical position, the support of the article is transferred from the first arm unit to a second arm unit which then pivots about a horizontal axis to tilt the flat article back to a horizontal position. Because the arm units of these patents must not only provide the entire support of the article from the start to conclusion of the turnover operation and because the mechanisms employed must accomplish the transfer of support of the article from one arm unit to the other at some point in the turnover cycle, the mechanisms employed are quite complex and of a dedicated design matched to the dimensions, particularly the thickness, of the article being handled.
The turnover apparatus of the present invention must handle vehicle wheel units whose thickness can vary over a substantial range from the relatively smaller-sized standard wheel units to the low-profile, wide-tread units employed on high-performance vehicles. The present invention presents a turnover device which will accomplish the turning over of vehicle wheel units of a reasonably wide range of dimensions by relatively simple mechanisms.